INFLUENCE OF TUMOR NECROSIS FACTOR α ON PAI-1 ACTIVITY AND mRNA LEVEL IN HUMAN UMBILICAL VEIN ENDOTHELIAL CELL AND THE MAPK REGULATORY EFFECT

Objective To study the influence of tumor necrosis factor α(TNF-α) on plasminogen activator inhibitor-1(PAI-1) activity and gene expression in human umbilical vein endothelial cell(HUVECs) and regulation of MAPK. Methods HUVECs were isolated,cultured and identified,The PAI-1 activity in HUVECs culture medium was measured by chromogenic assay.The concentration and time of TNF-α used to treat HUVECs were selected.The PAI-1 mRNA expression was determined by Northern blot.The effect of TNF-α on PAI-1 expression in HUVECs treated by MAPK inhibitor was observed. Results The PAI-1 activity was increased significantly when HUVECs were exposed to different concentrations and time of TNF-α in HUVECs.The PAI-1 mRNA level was increased in HUVECs after treatment with 1×10+5IU/L TNF-α for 18*!h.MAPK inhibitor(PD98059) could markedly inhibit the increase of PAI-1 activity and mRNA level induced by PAI-1.Conclusion The PAI-1 activity of HUVECs was increased after TNF-α exposure;The increase of PAI-1 activity was related to the increase of PAI-1 transcription; The MAPK may be involved in this process.